New Page — The Biology Primer

Selected Taxon

Animalia

Root

Multicellular eukaryotes with specialized cells and a blastula stage.

Key traitsMulticellularity, heterotrophy, no cell walls, specialized cells.

ExamplesSponges, cnidarians, worms, mollusks, arthropods, echinoderms, chordates.

Teaching noteClick a taxon to highlight its ancestry. Double-click a branch point to collapse or expand it.

Animalia

Read from left to right: each split marks a shared ancestor and a branching lineage.
Protostomia divides here into Lophotrochozoa and Ecdysozoa; Deuterostomia divides into Ambulacraria and Chordata.
Birds are nested within Dinosauria, Theropoda, Archosauria, Reptilia, and Sauropsida.
Porifera and Ctenophora placements vary across modern studies, so this page uses a simplified classroom arrangement.

Choose two taxa to find their most recent shared branch.

Which clade contains both Arthropoda and Nematoda?

Choose an answer to check your understanding.